Artificial marble used as all sort of interior materials/exterior materials, such as a kitchen countertop, flooring material, and the like can be largely divided into an inorganic-based artificial marble and a resin-based artificial marble. A type of the resin-based artificial marble from among these can be classified into an acryl-based artificial marble, unsaturated polyester-based artificial marble, and the like according to the used resins.
The acryl-based artificial marble takes up most of the artificial marble market because it has advantages, such as an excellent mechanical strength, the ability to express a beautiful color, an excellent thermal resistance, and the like, as compared with the unsaturated polyester-based artificial marble.
Generally, the acryl-based artificial marble is being produced by dissolving a high-molecular-weight acrylic material (ex. Polymethylmethacrylate (PMMA)) having about 100,000 of a weight average molecular weight in a curable monomer (ex. Methyl methacrylate (MMA)), and then applying the composition (resin syrup) prepared by mixing an additive, such as inorganic filler into a casting process that is a continuous way.
Meanwhile, for producing the acryl-based artificial marble, when using a pressing process, it can prepare products having various shapes as compared with that prepared using a casting process, and it has advantages such that the product produced from the pressing process has an excellent modification resistance, and it can be easily molded to a thin film product.
Therefore, if the composition having an acryl-based resin as a main component can be applied to the press molding, it is expected that the product having more excellent physical properties can be produced, that is, the product has both advantages of the acryl-based resin and the pressing process.
However, despite the advantages of the pressing process as mentioned above, the reason for producing the existed acryl-based artificial marble using the casting process is that the viscosity of the composition having the acryl-based resin as a main component is hard to increase to the level that can possible to apply the pressing process.
For example, when the content of the inorganic filler is increased in order to increase the viscosity of the resin composition, there were disadvantages such that the removing of bubbles is impossible, and the strength and the surface quality of the molded product are very deteriorated because the flowability has very become worse, with the increase of the viscosity.